Dave, Mike is correct. One should use low side for low freq and high for high freq regardless of rx and tx. Completely forgot about this.
73, ron, n9ee/r >From: [EMAIL PROTECTED] >Date: 2008/06/19 Thu PM 02:15:01 EDT >To: repeater-builder@yahoogroups.com >Subject: Re: [Repeater-Builder] 633-6a-2n notch duplexer > >The "10 dB" of pass loss is indicative of the RX and TX ports are "swapped". >Depending on what the duplexer was intended to connect to, ignore the RX/TX >labeling and think of the ports as HIGH and LOW. Look at the rx/tx frequencies >on the main label to let you know which is high and low. > >Best of luck, >Mike/W5JR > >---[Original Message]--- >From: [EMAIL PROTECTED] >To: Repeater-Builder@yahoogroups.com >Sent: Jun 19, 2008 2:04:15 PM >Subject: Re: [Repeater-Builder] 633-6a-2n notch duplexer > >Dave, > >I've tuned a number of these 633s and had no problems. They are pretty much >notch only with wide pass. Often get over 90 db notch with little, less than >1 db, insertion loss. > >I would think you have some internal problem, maybe from lightning. > >Wish I could help more. > >73, ron, n9ee/r > >>From: catdoogan1969 <[EMAIL PROTECTED]> >>Date: 2008/06/18 Wed AM 01:54:08 EDT >>To: Repeater-Builder@yahoogroups.com >>Subject: [Repeater-Builder] 633-6a-2n notch duplexer > >> >>hey guys, >> >>I've got my hands on a GR1225 repeater with an RFE4000a (Celwave >>633-2a-2n) notch duplexer and a phone patch. >> >>The repeater had some questionable solder problems on the output of >>the final due very likely to the poorly tuned duplexer. The solder >>was a quick fix and repeater has a healthy 30 watt output with clean >>rx (opening about .25uV). >> >>My current problem is the tuning of this duplexer, I started out with >>decent rx at the dx antenna input but no tx power was passing. >>Checked with watt meter at the tx port and had full reflect. Tried >>retuning tx side and lost rx sens. I can't seem to get either the rx >>or tx lined up now. I can get the notches placed right but the pass >>portion does not get much higher than -10dB (incoming set to 0dB) >>usually lower. >> >>Is there a start from scratch tuning procedure on these? I contacted >>celwave and they gave me a very simple tuning procedure. My problem >>is that I do not know what the original frequencies were on this >>duplexer. The documentation says that these units are good across >>450-470MHz but could there be certain frequencies that they just don't >>work well at. >> >>I am using an IFR 1900CSA Monitor with a tracking gen and a 50ohm load >>on the opposite port being tuned. >> >>Any thoughts on what I am doing wrong would be great...I'm starting to >>think I've over-promised on this unit. >> >>Thanks guys, >> >>Dave >> >> >> > >Ron Wright, N9EE >727-376-6575 >MICRO COMPUTER CONCEPTS >Owner 146.64 repeater Tampa Bay, FL >No tone, all are welcome. > > Ron Wright, N9EE 727-376-6575 MICRO COMPUTER CONCEPTS Owner 146.64 repeater Tampa Bay, FL No tone, all are welcome.
